Shock help

[jmpulse]

I am in need of some training on how the different adjustmenst effect how the shocks respond. I know the basics, but I don't quite know how the rebound effects how the supension reacts to jumps, whoops, bumps. I know the compression should be set to resist bottoming out, but how will it affect other items? How about adjusting the nitrogen pressures in the shocks? I know in my buddy's race car, a little pressure change makes a world of difference.

[RobRacing]

If you know the jist of suspension then it just takes trial and error to get it right. Go through whoops and bumps make a few adjustments the way you see fit and try again. Thats the only way to dial in any suspension system.

[jmpulse]

Ok. How will the shock pressure affect the shock?

[schmitthead]

i dont think its a good idea to mess with the pressure in the stock shocks. as for your rebound issue-- adjusting the rebound effects how fast the shock goes from compression to no compression. i hope this helps

[RobRacing]

Putting more pressure in the shocks will make them stiffer and dropping the pressure will make it softer. You need the proper guages and valves to do this type of work, you can't just realease the pressure like you would with air in your tires. You will also need a nitrogen source.

[jmpulse]

Originally posted by RobRacing
[B You need the proper guages and valves to do this type of work, you can't just realease the pressure like you would with air in your tires. You will also need a nitrogen source. [/B]

I have access to the schrader (sp?) valve, and the nitrogen. Would I then use the pressure to get the shock into the ball park, and then fine tune with the adjusters? How would taking the rebound to the extremes affect the handling?

[schmitthead]

you dont need to mess with the pressure, you can adjust the sh&t out of these shocks.

[2004TRX450R]

Do not adjust your pressure. It will make little to no difference anyway. The main reason for it is to have a cushion for when the shock compresses and the shaft displaces the oil. If there were no air in the shock it would explode because liquids don't compress. The rebound controlls how fast the shock will extend after being compressed. If it is to soft it will bounce back like a pogo stick and buck you off. But if it is to slowit will pack up on small quick bumps and whoops because it won't have enough time rebound before it hits the next bump. Each time it compresses more and more until it is completely bottomed and you have no suspension and then you get bucked again.

[SnellCRP]

Originally posted by jmpulse
I am in need of some training on how the different adjustmenst effect how the shocks respond. I know the basics, but I don't quite know how the rebound effects how the supension reacts to jumps, whoops, bumps. I know the compression should be set to resist bottoming out, but how will it affect other items? How about adjusting the nitrogen pressures in the shocks? I know in my buddy's race car, a little pressure change makes a world of difference.

This will take awhile.

1st - set your sag

As a general rule of thumb, the race sag dimension should be about one-third of the maximum travel. Your bike should be at normal racing weight, including fuel and engine oil, and wear all your gear.

Put the bike on a stand and measure the distance between a fixed point on the axle and one on the chassis somewhere.
Then get on the bike (all gear etc) and have a friend measure the distance between the same two marks that you measured when the bike was on the stand.
Subtract the two numbers and thats your race sag. Try to start at about 1/3 of the max travel and adjust to your personal preference from there.

2nd - rebound

Find a relatively fast straight with braking bumps leading into the entrance of a corner. Reduce the rebound damping until the rear end begins to hop or feel loose, then increase the rebound damping just until the hopping or looseness goes away.
Find a jump that tends to launch the quad out not up. The rear end should absorb the face and then smoothly lift the quad into the air, but if the rear end compresses and then bounces off the face, add rebound.
Find some large whoops. The quad should track straight through the whoops with the rear wheel extending to the ground before the next impact. If it dosen't, it is packing and the rebound damping should be reduced! This is not the setup for sand its for mx dirt.

3rd - compression

Find a corner with acceleration bumps on the exit. The rear of the quad should follow the ground. If the rear end hops and considerably looses traction, soften the compression. If this fails soften the rebound slightly.
Find some rough sections, a large jump. The shock should bottom on the roughest section but it should not be a slamming sensation. Add compression to fight bottoming, but avoid going to far because the little stuff will beat you to death. Remember the adjusters have a primary effect on the low speed, so even a large change in setting may only affect bottoming resistance slightly. Remember bottoming your suspension is not necessarily a bad thing. You should strive to bottom off the biggest bottoming load obstacle on the track. Whew, my brain hurts ;)

[jmpulse]

Originally posted by SnellCRP
This will take awhile.

Whew, my brain hurts ;)

Thank you very much. This is what I was looking for! Now it is time to go play!

[SnellCRP]

No problem, I love the in depth tech posts. :D

[schmitthead]

awesome reply dude!!!!!! thats what i need on my site.

[SnellCRP]

I clicked on your link is that your site?